Want an adjustable desk? We don't blame you. Everyone from funky startups to Hollywood execs are working up and knuckling down with productivity-boosting office furniture. It's the cool thing to do. (Not to mention, sitting all day is killing you). But you'll have to fork up a pretty penny if you want to buy a readymade adjustable desk. The crowd at Q&A site Stack Exchange offers some cheap DIY alternatives.

You could potentially use the pistons from some old office chairs, but you would have to make sure the desk top had enough weight to compress them (otherwise you would have to lean on the desk to make it go down). And you would have to physically lift the top to the desired height, which, depending on the weight, could pose a problem. You may also run into trouble engaging the lift/lower mechanism of all pistons simultaneously.

Alternative Answer: Simplify

You could eliminate a lot of the engineering and fabrication work by making a desk that has only two positions: standing and sitting.

I'm thinking of something using a four-bar linkage on each end of the desk to keep the work surface flat while you move it from one position to the other, with pins to keep it secured in either position.

You'd also want to incorporate some form of torque member to make sure the two linkages rotate together, to eliminate the need to always lift in the left-to-right center of the desk. Something like a closet rod might work for this. And if you want, you could adjust your linkage geometry so that in the standing position the surface had a slight tilt, but is flat in the sitting position.

Of course you'd be limited in how much stuff you could put on the desk because you'd be moving it by hand.

Alternative Answer: Double Up

Alternative Answer: Use Your Arm(s)

If you're mostly doing computer stuff, mount a monitor to the wall on an arm and use an adjustable keyboard trays don't have the necessary range of motion to accomodate both sitting and standing positions. The solution? D (the arm) Y.